1. Field of the Invention
The present invention relates to rifle sights, and particularly to removable iron sights. More specifically, the present invention relates to semi permanent backup iron sight.
2. Background of the Invention
Numerous detachable iron sights designs have been proposed, among which are the following:
U.S. Pat. No. 4,461,087 to Norman, titled xe2x80x9cFoldable Peep Sight;xe2x80x9d
U.S. Pat. No. 4,092,793 to Ricks, titled xe2x80x9cClip-On Sight Mount;xe2x80x9d and
U.S. Pat. No. 4,008,536 to Adams, titled xe2x80x9cDetachable Gun Sight.xe2x80x9d
Weapons such as the M16A4 Rifle and M4 Carbine with integral mounting rails for fire control and other devices are typically employed with a M68 red dot optic sight as the primary fire control device. The M68 mounts to the weapon through the use of a quick release rail grabber.
The current iron sight used as a backup to the M68 red dot sight also uses a quick release rail grabber configuration to attach to the mounting rail on the weapon. The size and configuration of the current detachable iron sight does not allow the iron sight and the M68 red dot sight to be mounted on the weapon at the same time.
A great and still unsatisfied need exists for a semi permanent backup iron sight that can be mounted and used on the weapon while the M68 red dot sight is still mounted on the weapon. A need also exists for a semi permanent backup iron sight that can be mounted and used on the weapon while other devices are also mounted on the weapon.
One feature of the present invention is to satisfy this long felt need to provide a quick attach/detach rail grabber backup iron sight that fits on the weapon while other devices are also attached to this weapon. This feature is accomplished by a folding sight that provides clearance for mounting various ancillary pieces of equipment to the rifle with the backup iron sight attached.
Another feature of the present invention is the use of a torsion spring to hold the sight aperture in the open position while allowing the sight aperture to move when a force is applied to it. This reduces the potential for damage to the sight aperture during rough handling.
Still another feature of the present invention is the use of an interference fit between the sight aperture and the sight aperture frame to act as a detent for positively holding the sight aperture in the closed, folded, or stowed position. Placing the sight aperture in the stowed position further reduces the number of parts required compared to a conventional mechanism, where the detent function would normally include several additional elements.
An additional feature of the present invention is the positioning of the elevation readings so that they are directly observable from the shooting position.
Another feature of the present invention is the use of an elevation adjustment mechanism in the form of a cam. The cam is designed to limit adjustment of the elevation mechanism to preclude inadvertently over rotating the elevation adjustment mechanism. This feature greatly reduces the potential for setting the elevation at other than the desired setting.